Electronic devices such as laptop computers, cellular telephones, and other equipment are sometimes provided with light sensors. For example, ambient light sensors may be incorporated into a device to provide the device with information on current lighting, conditions. Ambient light readings may be used in controlling the device. If, for example bright daylight conditions are detected, an electronic device may increase display brightness to compensate.
Ambient light conditions sometimes include significant changes in color. For example, an electronic device may be used in a cool color temperature environment such as outdoors shade or warm color temperature environment such as an indoors environment that is lit with incandescent lighting. Content that appears to be correctly displayed on a display in one of these environments may have an unpleasant color cast in the other environment. For example, a display that is properly adjusted in an outdoors environment may appear overly cool under incandescent lighting. To allow adjustments of display color based on ambient light color measurements, electronic devices may be provided with color ambient light sensors.
Ambient light sensor systems can be challenging to design. If care is not taken, ambient light sensors will be overly sensitive to the variations in the angle-of-incidence of light, will be affected by noise from infrared light, and will degrade due to environmental effects.